Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.
Orekhovich Institute of Biomedical Chemistry, 119121 Moscow, Russia.
Int J Mol Sci. 2023 Jan 8;24(2):1239. doi: 10.3390/ijms24021239.
Ganglioside GD2 is a well-established target expressed on multiple solid tumors, many of which are characterized by low treatment efficiency. Antibody-drug conjugates (ADCs) have demonstrated marked success in a number of solid tumors, and GD2-directed drug conjugates may also hold strong therapeutic potential. In a recent study, we showed that ADCs based on the approved antibody dinutuximab and the drugs monomethyl auristatin E (MMAE) or F (MMAF) manifested potent and selective cytotoxicity in a panel of tumor cell lines and strongly inhibited solid tumor growth in GD2-positive mouse cancer models. Here, we employed two different GD2-binding moieties-minibodies and scFv fragments that carry variable antibody domains identical to those of dinutuximab, and site-directly conjugated them to MMAE or MMAF by thiol-maleimide chemistry with drug-to-antibody ratios (DAR) of 2 and 1, respectively. Specific binding of the antibody fragment-drug conjugates (FDCs) to GD2 was confirmed in direct ELISA, flow cytometry, and confocal microscopy. Selective cytotoxic and cytostatic effects of the conjugates were observed in GD2-positive but not GD2-negative neuroblastoma and melanoma cell lines. Minibody-based FDCs demonstrated more pronounced cytotoxic effects and stronger antigen binding compared to scFv-based FDCs. The developed molecules may offer considerable practical benefit, since antibody fragment-drug conjugates are capable of enhancing therapeutic efficacy of ADCs by improving their pharmacokinetic characteristics and reducing side effects.
神经节苷脂 GD2 是一种广泛表达于多种实体瘤的成熟靶点，其中许多实体瘤的治疗效率较低。抗体药物偶联物（ADC）在多种实体瘤中取得了显著的成功，GD2 导向的药物偶联物也可能具有很强的治疗潜力。在最近的一项研究中，我们表明，基于已批准的抗体度伐鲁单抗（dinutuximab）和药物单甲基澳瑞他汀 E（MMAE）或 F（MMAF）的 ADC 在一系列肿瘤细胞系中表现出强大的、选择性的细胞毒性，并强烈抑制了 GD2 阳性的小鼠癌症模型中的实体肿瘤生长。在这里，我们使用了两种不同的 GD2 结合部分——单价抗体和 scFv 片段，它们携带与度伐鲁单抗相同的可变抗体结构域，并通过硫醇-马来酰亚胺化学将其分别与 MMAE 或 MMAF 直接连接，药物与抗体的比率（DAR）分别为 2 和 1。抗体片段-药物偶联物（FDC）与 GD2 的特异性结合在直接 ELISA、流式细胞术和共聚焦显微镜中得到了证实。在 GD2 阳性而非 GD2 阴性的神经母细胞瘤和黑色素瘤细胞系中观察到了偶联物的选择性细胞毒性和细胞抑制作用。单价抗体 FDC 与 scFv FDC 相比，表现出更明显的细胞毒性作用和更强的抗原结合能力。由于抗体片段-药物偶联物能够通过改善其药代动力学特性和减少副作用来增强 ADC 的治疗效果，因此这些开发的分子可能具有很大的实际意义。
